For example, semiconductor devices, liquid-crystal display devices, or the like are manufactured using a projection exposure apparatus for projecting a pattern of a mask (reticle, photo-mask, or the like) through a projection optical system onto a plate (glass plate, semiconductor wafer, or the like) coated with a resist. The conventional projection exposure apparatus frequently used was one (stepper) for implementing one-shot exposure of a pattern of a reticle in each of shot areas on a plate by the step-and-repeat method. Recently suggested is the projection exposure apparatus of the step-and-scan method having a plurality of small partial projection optical systems with a magnification of 1× arranged in two or more rows at a predetermined interval along a scanning direction, instead of one large projection optical system, and adapted to project patterns of a mask onto a plate through the respective partial projection optical systems to effect exposure thereof, while scanning the mask and the plate relative thereto.
The plate is increasing its size in recent years and the plate over 2 m×2 m has been used. When the above-described exposure apparatus of the step-and-scan method is used to implement exposure on the large-size plate, the mask also has a large size because the partial projection optical systems have the magnification of 1×. The larger the size, the higher the cost of the mask becomes because it is also necessary to maintain flatness of a mask substrate. In addition, since masks for four to five layers are needed to form an ordinary TFT part, considerable cost was required. Therefore, the projection exposure apparatus proposed is one wherein the magnification of the projection optical systems is set to an enlargement magnification, thereby decreasing the size of the mask (Japanese Patent Application Laid-open No. 11-265848).